Ana Paula Barbosa Martins

• Doctor of Philosophy
• Dalhousie University

Sawfishes are the most endangered cartilaginous fishes on the planet. Their external morphology facilitates entanglement in fishing nets and their K-selected life history hinders the recovery of exploited populations. The Eastern Amazon coast (EAC) is known to be an area where sawfishes occur in Brazil, but few studies have been conducted in the ar...

This paper describes the record of a gravid Pristis pristis from the north coast of Maranhão State (Brazil) in May of 2009 by an artisanal vessel. Size, mass and rostrum length of the adult female were estimated at 5000 mm, 750000 g and 1536 mm, respectively. Total length (LT ) of miscarried embryos ranged from 755 to 800 mm and total mass from 890...

Sexual dimorphism is a widespread feature in several groups of vertebrates. Chondrichthyans differ sexually due to the presence of the clasper, a structure for internal fertilization, and other sexual differences in secondary characteristics. Nevertheless, studies assessing these variations are fairly rare. The main goal of this study is to identif...

Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable speci...

Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The pres...

Skates and rays (Batoidea) play a significant ecological role, contributing to ecosystem services through bioturbation and acting as vital intermediate components of the trophic chain in various aquatic environments. Despite their wide global distribution and ecological importance, batoids receive less attention than their shark relatives, resultin...

As pescarias artesanais no Maranhão capturam diversas espécies de tubarões e raias, com predominância de indivíduos imaturos. Monitoramentos realizados em 2023 e 2024 registraram 443 espécimes (277 tubarões e 166 raias) de 15 espécies, destacando o Tubarão-martelo-recortado, o Tubarão-anequim e a Raia-de-focinho-comprido como os mais capturados. A...

In the 20 years since the IUCN SSC Shark Specialist Group’s first status report (2005), much has changed for sharks, rays and chimaeras. This report updates our understanding, and the scope of information reflects the scale of these two decades of change. The breadth of research topics has expanded, mirroring the inclusion of a greater diversity of...

The Shortfin Mako (Isurus oxyrinchus) is a pelagic species found in tropical and temperate waters worldwide. Despite being listed as Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, Shortfin Mako remains one of the most frequently captured species by industrial fleets and raising concerns about...

Data on the movement and space use of aquatic animals are crucial to understand complex interactions among biotic and abiotic components of ecosystems and facilitate effective conservation and management. Acoustic telemetry (AT) is a leading method for studying the movement ecology of aquatic animals worldwide, yet the ability to efficiently access...

Information on how the trophic ecology of predators shapes their movement patterns and space-use is fundamental to understanding ecological processes across organisational levels. Despite this, studies combining spatial and trophic ecology to determine how prey preference and/or resource availability shape space use are lacking in marine predators...

methods used, as well as the outcome or objectives targeted for each method. In addition to summarizing the use of complementary methods and their outcomes, we discuss how they supplement acoustic telemetry and other tracking approaches. Our review shows that using additional methods to support telem-etry data helps expand the breadth of research q...

Chapter 4 Shark conservation and fisheries management across the globe Whether humans are harvesting shark meat and shark fins for consumption, sale, trade, or religious/cultural ceremonies, human behavior, and beliefs shape the way we catch and utilize shark and ray products. The historic, social, cultural, and economic components of fisheries are...

Plastics represent the largest component of marine debris globally. In this context, it is essential to quantify the current extent of plastic pollution, including microplastics (MP; plastics < 5 mm), within marine abiotic and biotic compartments. Despite significant effort, MP studies still face methodological impediments to establish accurate and...

Over the past 4 decades there has been a growing concern for the conservation status of elasmobranchs (sharks and rays). In 2002, the first elasmobranch species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Less than 20 yr later, there were 39 species on Appendix II and 5 o...

Nursery areas are crucial for many elasmobranch species, providing advantages such as increased access to prey and reduced predation risk. This study investigated the trophic interactions of two juvenile stingray species within a coastal communal nursery using stable isotope analysis. Muscle, plasma and red blood cells samples were taken from the m...

Os ferimentos causados por arraias de água doce são comuns entre os pescadores. A raia Potamotrygon motoro apresenta um ferrão com uma ponta afiada e pontas serrilhadas espalhadas bilateralmente, os ferrões possuem toxinas que promovem a vasoconstrição, causando dor imediata e isquemia. Esses acidentes são extensos e podem manter as vítimas impossi...

Acoustic telemetry (AT) is a rapidly evolving technique used to track the movements of aquatic animals. As the capacity of AT research expands it is important to optimize its relevance to management while still pursuing key ecological questions. A global review of AT literature revealed region-specific research priorities underscoring the breadth o...

The injuries caused by freshwater stingrays are common among fishermen. The raya Potamotrygon motoro en the features a stinger with a sharp edge and serrated tips spread bilaterally, the stingers have toxins that promote vasoconstriction, causing immediate pain and ischemia. These accidents extensive and could keep victims unable to work from weeks...

Stingrays are a diverse and widespread group of elasmobranchs. Despite their ecological and economical importance, many aspects of stingray ecology remain poorly understood. Few studies have examined fine-scale movements of juvenile stingrays within nursery areas. This study aimed to examine diel movement patterns in juvenile mangrove whiprays (Uro...

Stingrays are thought to play important ecological roles in coral reef ecosystems. However, little is known about juvenile stingray movement patterns and habitat use in coral reefs. This study used active acoustic telemetry to determine fine-scale diel movement patterns and habitat use of juvenile cowtail stingrays (Pastinachus ater) in a coral ree...

Overfishing can lead to stock collapses of both target and bycatch species. In some cases, unregulated fishing activities can even drive species towards extinction. Batoids comprise a significant portion of the bycatch of fisheries targeting teleost fishes. In Brazil, the Amazon coast is the second largest landing area in the country for these orga...

Overfishing can lead to stock collapses of both target and bycatch species. In some cases, unregulated fishing activities can even drive species towards extinction. Batoids comprise a significant portion of the bycatch of fisheries targeting teleost fishes. In Brazil, the Amazon coast is the second largest landing area in the country for these orga...

Northern Brazil is a global hotspot for elasmobranch conservation, and Maranhão state is an area of great ecological importance for the group within this region. Maranhão has one of the highest elasmobranch bycatch rates in the country, however management plans or risk assessments have never been developed for the state. This review aimed to gather...

GPS telemetry provides high-accuracy spatial data on animal movement; however, it has rarely been used with benthic organisms, such as stingrays, because of their irregular surfacing behaviour or bottom-dwelling habits. This study evaluated the use of towed-float GPS tags to assess movements of juvenile stingrays, with active tracking performed sim...

The Daggernose Shark Isogomphodon oxyrhynchus is an endemic species of the Northern Coast of South America distributed from Trinidad & Tobago to Brazil's Amazon Coast. Due to increasing fishing efforts and its limited distribution range, the Daggernose Shark is one of the most endangered shark species in the world (CR). Further threats arise from m...

Nursery areas are critical to the survival of many marine species, and it is widely accepted that elasmobranch species use nursery areas where they improve species fitness. A 2007 review proposed an approach to identify elasmobranch nursery areas to help clarify their location and use. Here we examine progress towards defining elasmobranch nurserie...

Nursery areas are crucial for many elasmobranch species, providing benefits that increase fitness and survival. Shark nurseries are well studied and our knowledge of their function and importance has expanded over the past few decades. However, little attention has been given to batoid nurseries, with studies covering less than 6% of the 663 curren...

Interview questions. (DOCX)

Consumption of shark products: How to achieve sustainable fisheries in poor communities? Developed online: https://magic.piktochart. (TIF)

Since 1989, specimens of the non-native mud sleeper Butis koilomatodon (Bleeker, 1849) (Perciformes: Eleotridae) have been collected off of the Brazilian coastline. The species has the potential to invade marine and estuarine systems, and outcompete native fish. The present study reports an additional occurrence of B. koilomatodon in the intertidal...

Elasmobranchs are predators of marine and estuarine environments throughout the world. Due to their life history features, such as late sexual maturity, slow growth and low fertility rates, they are susceptible to extinction when overexploited. Coastal tropical elasmobranchs rely on habitat availability to reproduce, especially mangrove forests. Th...

Bull sharks are a cosmopolitan shark species frequently found in shallow shelf ocean waters and, occasionally, in several tropical river systems around the world. Due to bull shark's capability to enter riverine systems, the documentation of its occurrence is essential for future fisheries inspections and studies. In this way, this study aims to re...